A range of very high quality Ribbon tweeters with metal face
plates, aluminium ribbons, and neodymium magnets and superb sound reproduction.
The advantage of the ribbon is that it has 10 times the force to mass ratio that
a dome tweeter would have, and so is faster and more detailed. The Fountek
are
some of the best and most consistent Ribbon tweeters available, having a
transparent but not harsh sound quality. Sold in matched pairs. We
recommend a 2nd order crossover.. .Warning Ribbons must never be used
without a crossover, and unless you have good measuring equipment it is not
recommended that you use these tweeters as direct replacements for dome
tweeters. When they are operating correctly they will outperform most dome
tweeters due to a superior force to moving mass ratio. Unfortunately because of
the extra work and testing required to produce consistently good results these
ribbons only tend to be used in the very best of speakers.

IPL Matched Units, The frequency
response and sensitivity of Ribbons tend to vary far more than conventional dome
tweeters , for this reason IPL will carry out response and sensitivity checks on
every tweeter used in IPL Kits and match the tweeters to within 0.33db. In
this case the tweeter is placed in the specific cabinet with the bass unit and
crossover, and measurements taken. IPL matched units are then boxed and marked
with the appropriate kit and the varying crossover component values. (any
tweeters we cannot match are rejected, hence the on-cost of the matched units).

It is IPL experience that within a batch of 50
units there can be up to 3db variation and even the supplied matched pairs can
vary by up to 1db (an audible difference) For this reason these time consuming
tests on every tweeter are essential, and it is noted that every crossover for
the same kit type will be different , so after building your kit it is essential
to keep your specific set of instructions.